It is known in practice that highly compressed pressed bales can be produced in a baling press. Such baling presses usually have a prepress, in which material to be pressed is accumulated, optionally in a plurality of batches, and precompressed into a pressed bale. The pressed bale is subsequently subjected to final pressing into a highly compressed pressed bale in a finishing press under high pressing pressure. On the one hand, rotary presses are known in this connection, for example, according to EP 0 695 690 A1, in which the precompressed pressed bales are placed together with the pressure rams and the press box from the prepress into the finishing press with a rotary table. At the same time, an emptied press box is turned back from the finishing press to the prepress.
On the other hand, it is known from WO 02/38364 A1 that the press box of a prepress can be provided with a displaceable rear wall, a front wall that can be folded outwards and upwards by 90° as well as with a press box underside extended under the rear wall. With the front wall of the press box folded up, the underside of the press box with the displaceable rear wall can be displaced in the direction of a finishing press in a prepress of this type, and the folded-up front wall and the displaced lower wall come into contact with the upper and lower pressure rams of the finishing press and the precompressed pressed bale is pushed into the finishing press through the displaceable rear wall. The folded-up front wall and the displaceable underside of the press box form a channel here, in which the precompressed pressed bale can be displaced.
A packaging device for precompressed pressed bales is likewise known from WO 02/38364 A1. A film curtain can be hung between the end of the channel formed from the front wall of the press box and the underside of the press box and the pressure rams of the finishing press. When the precompressed press box is pushed into the finishing press, the film curtain is fixed at the lower end while more film material is fed from the upper end. The film forms a loop here, which is wound around the precompressed pressed bale during the inserting motion into the finishing press. The film is applied directly on the pressed bale. To prevent the film loop, which is pulled through between the pressure rams and the bale under pressure while the pressed bale is being pushed in, from tearing, only a low precompressing pressure is possible, on the one hand, and, on the other hand, a comparatively thick film material with high load-bearing capacity and a thickness of 100 μm or more is necessary.